Field of the Invention
The invention relates to an electronic control unit, in particular for a device provided in a motor vehicle, including a computer, a first data memory and a second data memory connected to a temperature sensor, wherein data are transmitted from the first to the second data memory.
Such a control unit is disclosed in U.S. Pat. No. 4,181,944, for example.
Modern electronic control units are increasingly being fitted to actuators to be controlled or integrated in them. In the field of motor vehicle technology, the following may be mentioned as examples of such control units: Transmission controllers integrated in transmissions (so-called Prodmod transmission controllers), integrated hydraulic and electronic systems and engine controllers installed in internal combustion engines.
As a result of attaching the control units to the mechanical and hydraulic devices in that way, the electronic circuits are subjected to increased stresses, in particular to higher temperatures, due to their environment. Thus, for example, temperatures of up to 140.degree. C. or more may occur in automatic transmissions. The meaning thereof is that the electronic components have to be operated right up to the limits of their technical specifications.
Those components that are stressed to a greater extent include, in particular, electrical program and data memories, to which type-specific data and adaptive values of the control unit (for example learning values for wear compensation) are written and which must ensure protected management of such data. Examples of such memory modules are EEPROM and flash modules. Their task is to store variable data (for example learning values, diagnostic information, fault memory contents or calibration values) even when the control unit is disconnected from its supply voltage.